Railraod car supsension system

ABSTRACT

The present invention includes a suspension system for use with railroad freight car trucks, or the like, wherein vertical, transverse and longitudinal movements of the car body sprung mass are restrained and dampened by captive elastomeric means having a progressively increasing spring rate in all three of said directions. This system is self-centering, self-dampening and provides progressive resistance to increased forces of maximum amplitude in said three directions, without requiring elastomeric shear forces to accomplish the aforesaid.

United States Patent 1191 Willetts 1 July 22, 1975 [54] RAILRAOD CARSUPSENSION SYSTEM 3,735,711 5/1963 Hassenauer 267/3 X R8,38l 8 1878 H' l105 224.1 [76] Inventor: Elwood u. Willetts, 102 s. ey Penataquit Ave.,Bay Shore, NY. FOREIGN PATENTS OR APPLICATIONS 11706 141,937 6/1935Austria 105/224.1 [22] Filed: June 17, 1974 Primary Examiner-Robert S.Ward, Jr. [211 App! 479751 Assistant ExaminerHward Beltran Attorney,Agent, or Firm-Paul .I. Sutton [52] U.S. Cl l/224.l; 267/3 [51] Int. Cl.B6lf 5/30; B61f /06; Fl6f 1/44 57 ABSTRACT [58] Field of Search /197 A,197 R, 224.1; I l v 2 7 3 4 3 A 3 2 0 045 R The present mventionincludes a suspension system for use with railroad freight car trucks,or the like, 5 References Cited wherein vertical, transverse andlongitudinal move- UNITED STATES PATENTS ments of the car body sprungmass are restrained and dampened by captive elastomeric means having apro- 139362 6/1873 Bndges 267,3 gressively increasing spring rate in allthree of said di- 148,6l8 3/1874 McCarthy... lO5/224.1 1 1f lfd 7205/1874 Shattuck 105/226.1 recnons'. Se icemermgtse ampenmg 2 13754311/1938 Piron I t 105324. and provides progressive resistance tomcreased forces 3:352:255 11/1967 Sheppard 105/197 R of maximumamplitude in Said three directions With- 3,5l8,948 7/1970 King et al.105/197 A x out requiring elastomeric shear forces to accomplish3,572,745 3/1971 Willetts 1 1. 280/1045 R the aforesaid. 3,606,2959/1971 Appleton 267/63 R 3,687,478 8/1972 Willetts 280/1045 R 1 Clam, 7Drawmg Figures SHEET PATENTED JUL 2 2 I975 FIG RAILRAOD CAR SUPSENSIONSYSTEM This application is related to the structure of my copendingapplications Ser. Nos. 356,496, filed May 2, 1973 and 293,648, filedSept. 29, 1972, both of which are continuation-in-part applications ofmy application Ser. No. 123,581, filed Mar. 12, 1971, now US. Pat. No.3,687,478 granted Aug. 29, 1972. US. Pat. No. 3,687,478 furtherdiscloses improvements over the subject matter contained in my US. Pat.No. 3,572,745 dated Mar. 30, 1971. US. Pat. No. 3,572,745, itself, is acontinuation-in-part of application Ser. No. 721,558, filed Apr. 1,1968, now abandoned, and application Ser. No. 649,502, filed June 28,1967, now abandoned. The subject matter of my aforementionedapplications and my US. Pat. Nos. 3,572,745 and 3,687,478 is herebyincorporated by reference into the present specification.

This invention relates generally to vehicle suspension systems and moreparticularly to a vehicle suspension system for use with a railroad cartruck or the like for isolating vertical, transverse and longitudinalforces that are normally encountered during operation from the sprungmass.

I have made many inventions which have solved the problems associatedwith isolating road-induced excitations from the sprung mass of varioustypes of vehicles. The aforementioned list of patent applications andpatents represent but a few of my efforts to protect inventions whichovercome prior art problems associated with the isolation of forces andvibrations as between the driver or vehicle cargo, on one hand, andoperationally induced vibrations, on the other hand. My ef forts havebeen successful, as can be attested to in any number of tests conductedby me.

My more recent efforts to provide superior and economical suspensionsystems have included the provision of vehicle suspension systemsutilizing one or more elastomeric members capable of exhibiting aprogressively increasing spring rate under increasing loads. In the caseof truck and trailer suspensions, for example, road-induced excitationsare isolated as between neighboring axles as well as between these axlesand the ve hicle sprung mass. Unlike many known or prior art suspensionswhich, because of their structure, transmit these excitations to thevehicle sprung mass and to the vehicle driver himself, my suspensionsystems have been able to overcome this rather serious drawback whichrepresents not only a health hazard to the vehicle driver, but rathergreat economic losses each year to the owners of damaged cargo. Sufficeit to say that the vehicle industry is constantly on the alert andreceptive to suspension structures capable of overcoming these problems.

Before proceeding further with a discussion of the present invention, itwill be useful here to devote some words to the question of vibrationsof the type normally exhibited in vehicles and their associatedsuspension structures. The occurrence of vibrations is obviously quitewidespread. While many uses of vibrations harness this energy to causefavorable or helpful uses, such as using vibrations to relieve internalcooling stresses in castings and to study the process of aging, thereare a large number of rather bad effects caused by vibrations. Thephenomenon of resonance or nearresonant conditions create high stressesand very often hasten the time when eventual structural failure mayoccur. Moreover, vibration has a bad psychological effect on people inthe vicinity in that it is tiring, slows production and creates agenerally undesirable condition.

Basically speaking, vibrations occur in elastic systems that consist ofone or more masses connected to each other or to a fixed member bysprings. The phenomenon of vibration is the motion of a body or systemthat is repeated after a given interval of time known as the period. Thenumber of cycles of motion per unit of time is called the frequency. Themaximum displacement of the body or some part of the system from theequilibrium position is commonly referred to as the amplitude of thevibration at that point.

There are two general types of vibration, namely: rectilinear andtorsional. Rectilinear vibrations appear in two basic forms: thelongitudinal form is the axial compression and extension of bars andwires and include the compression and extension of springs of the coiledtype, for example; the transverse rectilinear vibration is seen in themotion of beams perpendicular to their centerline. The motion oftorsional vibrations is one of oscillation or twisting, as in the caseof shafts, and their amplitude is measured in radians or degrees, asopposed to inches in the case of rectilinear vibrations.

When a body or system is given an initial displacement from theequilibrium position and released, it will vibrate with a definitefrequency known as its natural frequency. This vibration is said to befree since no external forces act upon it after the initialdisplacement. The body vibrates with decreasing amplitude until it comesto rest. This reduction in amplitude is caused by a loss of the totalenergy in the system, known as damping and may be due to friction orresistance, etc. In some cases where the amount of damping is verylarge, the body will not vibrate but may merely creep back to theequilibrium position and its motion is said to be aperiodic.

In conditions of the type normally associated with vehicles and vehiclesuspension systems, an unbalanced vibrational system is created wherethe body or system is subjected to periodic external forces of the typenormally associated with operational excitations induced by road or railconditions. In such cases a forced vibration occurs and if the frequencyof this external force is the same as the natural frequency associatedwith the mass involved, resonance takes place. The body or system thenvibrates with large amplitudes, which result in high stresses andpossible interference of parts. Problems associated with resonantvibrational conditions are greatly increased in cases where transient ortemporary vibrations are super-imposed upon steady-state vibrations,since the resultant motion is the vector sum of the two motionsconsidered independently.

The foregoing discourse concerning vibrations is meant only tofamiliarize the reader with the terminology normally used in connectionwith vibrational problems and to render an outline of the elementsmaking up resonance, which is an undesirable phenomenon sought to beovercome by this and many of my previous inventions.

The present invention concerns itself with a vehicle suspension systemwhich will be described for use with railroad car trucks. However, Iwish to emphasize here that the present invention may be equally wellsuited for many other applications involving vehicles other thanrailroad cars. The use of a railroad car truck as an example indescribing this invention should in no way limit in the mind of thereader this vehicle suspension system, since it is equally well suitedin concept and structure for use with other types of vehicles.

It is an object of the present invention to provide a vehicle suspensionsystem featuring a progressively increasing spring rate and capable ofisolating vertical, transverse and longitudinal impacts and loads.

Another object of the present invention is to provide a vehiclesuspension system capable of reducing and eliminating undesirableresults associated with vertical, transverse and longitudinal dynamicimpacts, static transverse roll, and resonance (and metallic noise)resulting from lost motion.

A further object of the present invention is to provide a suspensionsystem, as above, which includes demountable truck side bearings onwhich all load is carried, without the use of a centerplate. Thissuspension system will provide a plate which serves as a bolster, withan offset kingpin carried inboard of a shortened wheel base car truck.

A further object of this invention is to provide a vehicle suspensionsystem which will weigh less than conventional suspension systems, willreduce cargo damage in transit, will reduce wheel and rail wear, willreduce or eliminate resonance and their associated derailments, andwhich will reduce noise.

Yet another object of the present invention is to provide a vehiclesuspension system which will provide to the user improved operationalcharacteristics, including, without limitation, the isolation ofvertical, trans verse and horizontal impacts of rail joints, switchpoints, curves and brake forces from the truck frame.

Another object of this invention is to provide a vehicle suspensionsystem which exhibits a progressively increasing spring rate by use of asubstantially spherical elastomer captively housed between upper andlower spring seat members, each of which include vertically extendingwalls or flanges which provide a boundary within which the sphericalelastomer is situated. Optional pilot members associated with either oneor both of the upper and lower spring seat members may extend intoaxially aligned cavities or recesses formed in the elastomeric memberitself, thereby maintaining the desired alignment between these seatmembers and the elastomer captively held therebetween.

Yet a further object of this invention is to provide a vehiclesuspension system for use with railroad freight car trucks, or the like,wherein vertical, transverse and longitudinal movements of the car bodysprung mass are restrained and dampened by a captive sphericalelastomeric member exhibiting a progressively increasing spring rate inall three of said directions, and in which the system is self-centering,self-dampening and provides progressive resistance to increased forcesof maximum amplitude in said three directions, without requiringelastomeric shear forces to accomplish the aforesaid.

Another object of this invention is to fulfill all of the aforementionedobjects and overcome the limitations and disadvantages of prior artsuspension structures and systems. According to one aspect of theconcept of the present invention, the novel means or steps which areemployed to overcome the disadvantages of the prior art include avehicle suspension system for use with a railroad freight car equippedwith car trucks having at least one axle, and comprising a journal boxdisposed at each transverse end of the axle. Left and rightlongitudinally extending vehicle side frame members are disposed at eachtransverse side of the freight car. A pair of lower seat members aredisposed fore and aft of the axis of the axle and are each supported bythe journal box. A cooperative pair of spaced upper seat members aresecured such that they are integral with the left frame member, forexample, during use. A pair of elastomeric members of spherical crosssection are disposed intermediate and captively held between each pairof upper and lower seat members such that each of the elastomericmembers provides a progressively increased resistance to vertical,transverse and longitudinal operating forces transmitted between thesprung mass of the vehicle and the axle referred to above.

My invention will be more clearly understood from the followingdescription of specific embodiments of the invention, together with theaccompanying drawings, wherein similar reference characters denotesimilar elements throughout the several views, and in which:

FIG. 1 is a side elevational view of a railroad freight car equippedwith the vehicle suspension system according to the present invention;

FIG. 2 is an enlarged fragmentary sectional elevational viewillustrating the vehicle suspension system provided by this invention;

FIG. 3 is a fragmentary sectional plan view looking along line 33 ofFIG. 2',

FIG. 4 is an enlarged fragmentary sectional elevational viewillustrating the relationship between the elastomeric member accordingto this invention and its associated upper and lower spring seatmembers;

FIG. 5 is an enlarged, perspective, exploded view illustrating theelastomeric member and the upper and lower spring seat members of FIG.4;

FIG. 6 is a fragmentary sectional plan view illustrating a truncatedcylindrical elastomeric member according to an alternate embodiment ofthis invention; and

FIG. 7 is a view similar to that of FIG. 6 wherein a cubical orrectilinear-shaped elastomeric member is illustrated.

Before describing this invention in detail with respect to the drawingsannexed hereto, it should be noted that following the description of thedrawings and the components of the invention disclosed therein, variousstructural features of my invention will be amplified and expounded uponboth with respect to the drawings and with respect to theircharacteristic features.

Referring now in more detail to the drawings, FIG. 1 illustrates arailroad freight car 10 of a conventional type normally used to transfercargo, which is equipped with car truck assemblies 11 and 12. Each ofthese car truck assemblies 1 1 and 12 include a plurality of wheels 13of a conventional type, usually 33 inches in diameter, and which areadapted to ride upon rail 14. While it is not necessary in thisspecification to describe in detail the features of conventionalrailroad freight car such as freight car 10, suffice it to say thatfreight car 10 is of the type having a slidable door 15 which is guidedbetween its open and closed positions by tracks 16. It is intended thatthe present invention be capable of use with conventional box cars ofthe type manufactured by the Pullman-Standard Division of Pullmanincorporated of Chicago, Ill.

FIGS. 2 and 3 illustrate in more detail the interrelationships betweenthe elements of my invention. A vehicle side frame member 17 is shown inFIGS. 2 and 3 extending in a longitudinal direction with respect to thelongitudinal axis of railroad freight car 10. Side frame member 17represents one of a pair of side frame members, located at transversesides of freight car 10, respectively. A plate bolster member 18represents the freight car truck bolster and is secured by bolts orother conventional fastening means, via bracket assembly 19 to each ofside frame members 17. Where greater structural integrity or anincreased moment of inertia is required or desired, one or more ribs 20may be added to bolster member 18. Bolster member 18 is sufficientlystrong to more than adequately support vehicle braking gear (not shown)along its length and intermediate side frame members 17. A six inchpin-kingpin trunnion assembly 21 of a conventional type is shown inFIGS. 2 and 3 pivotally secured to a car center sill 22. Kingpintrunnion assembly 21 is located inboard of bolster member 18, as labeledin FIG. 3, and may alternatively be ofa ball bushing type capable ofaccommodating oscillation only, without vertical load.

Axles 23 and 24 are shown in plan view in FIG. 3 extending betweenwheels 13 and their opposing wheels on the opposite side of each ofaxles 23 and 24. The journalling of the ends of axles 23 and 24 is alsoseen in FIGS. 2 and 3 as being accommodated by journal box assemblies 25and 26, respectively. For purposes of convenience, the stub ends ofaxles 23 and 24 have been given the same reference characters as theirassociated axles, and are shown extending into journal box assemblies 25and 26, respectively, in FIG. 3. Journal box assemblies 25 and 26 houseand support journal bearing assemblies 27 and 28, respectively. In apreferred embodiment of the invention, the inner race 29 ofjournalbearing assembly 27 turns with axle 23, while the outer or stationaryrace 30 is integral with the base ofjournal box assembly 25. Similarly,the inner bearing race 31 of journal bearing assembly 28 turns with axle24 while its associated outer bearing race remains stationary and isnormally integral with journal box assembly 26. It is contemplated bythe present invention that journal bearing assemblies 27 and 28 may beremovable and/or interchangeable.

Turning now to the structural configuration of the present inventionwhich provides a progressively increasing spring rate with increasingloads in all three of the vertical, transverse and longitudinaldirections, it is seen if FIGS. 2, 4 and 5 that journal box assemblies25 and 26, respectively, support pairs of lower spring seat members 33and 34, and 35 and 36, each of which is secured such as by welding orother conventional fastening means to upper surfaces 37, 38, 39 and 40of journal box assemblies 25 and 26, respectively. Each of lower springseat members 33, 34, 35 and 36 is formed with upstanding, substantiallyvertically extending walls or flanges 41, 42, 43 and 44, respectively.Walls or flanges 41, 42, 43 and 44 are each preferably arched such thatadjoining portions thereof extend halfway aboout the periphery of thebase thereof. For purposes of illustration only, FIG. 5 represents anexploded view of the interrelationship between the members beingdescribed now and is representative of each of the combination ofelements associated with lower spring seat members 33, 34, 35 and 36.Thus, each of said lower spring seat members includes a base portion 45thereof (FIG. 5 above which wall portions 46 and 47 comprise wall orflange 44, for example. Wall portions 46 and 47 extend in an archedmanner and at certain points thereof extend substantially 90 withrespect to one another.

The inside lower surfaces of lower spring seat members 33, 34, 35 and 36are each formed with concave or cup-shaped surfaces 48, 49, 50 and 51,respectively. The specific shape of cup-shaped surfaces 48, 49, 50 and51 may be predetermined and, thus, may be spherical, elliptical, oranypredetermined or desired shape. Lower pilot members 52, 53, 54 and 55are integral with cup-shaped surfaces 48, 49, 50 and 51, respectively,and may be either integrally formed with these surfaces or may beseparately formed and secured thereto. Each of these pilot membersextend substantially vertically from the center of its associatedcupshaped surface a distance substantially short of the height of thewall or flange associated with the same cup-shaped surfaces. Each of thepilot members 52, 53, 54 and 55 is somewhat tapered such that theyterminate in a rounded diameter which is substantially lesser inmagnitude than the diameter of the pilot members at the point ofjuncture with its associated cup shaped surface. 9

FIGS. 2, 4 and 5 further illustrate the existence of two pairs of upperspring seat members 56, 57, 58 and 59, associated with journal boxassemblies 25 and 26, respectively. As in the case of each of the lowerspring seat members 33, 34, 35 and 36 described in detail above, each ofupper spring seat members 56, 57, 58 and 59 may be and preferably are ofidentical structure or structural configurations. This provides forstandardization and accompanying reductions in cost. It should befurther noted that all of the lower and upper spring seat members maylikewise be identical in structural configuration for these samereasons. Thus, as in the case of the lower spring seat members justdescribed, each of upper spring seat members 56, 57, 58 and 59 is formedwith a pair of arched, adjoining wall portions 60 and 61 which extendhalfway around the peripheral of a base portion 62 of each. Wallportions 60 and 61 depend vertically from their respective base portionswhich, in turn, are each secured, such as by welding or otherconventional means, to the underside of side frame member 17.

As in the case of the lower spring seat members, each of the upperspring seat members is formed with a concave or cup-shaped surface 63,64, 65 and 66, with respect to members 56, 57, 58 and 59, respectively.Upper pilot members 67, 68, 69 and 70 similarly extend vertically fromtheir associated cup-shaped surfaces 63, 64, 65 and 66, respectively andare axially aligned with respect to lower pilot members 52, 53, 54 and55, respectively. In this way it can now be seen and further illustratedin FIG. 2 that lower spring seat members 33, 34, 35 and 36 are inopposing and aligned spaced relationship with respect to upper springseat members 56, 57, 58 and 59, respectively. A spherical elastomericmember is captively disposed between each of the aforesaid opposingpairs of upper and lower spring seat members.

More specifically, elastomeric member 71 is disposed intermediate andcaptively held between lower spring seat member 33 and upper spring seatmember 56. Elastomeric member 72 is disposed intermediate and captivelyheld between lower spring seat member 34 and upper spring seat member57. Elastomeric members 71 and 72 are associated with journal boxassembly associated with axle 23. Referring now to journal box assembly26 which is associated with axle 24, elas tomeric member 73 is disposedintermediate and captively held between lower spring seat member andupper r ring seat member 58. Likewise, elastomeric member 74 is disposedintermediate and captively held between lower spring seat member 36 andupper spring seat member 59.

Each of elastomeric members 71, 72, 73 and 74 is preferably formed in asubstantially spherical shape when in an unloaded or free condition.Axially aligned recesses 75 formed in diametrically opposite ends ofeach of these elastomeric members accommodate the entry of a pilotmember associated with the aforementioned upper and lower spring seatmembers. Thus, when assembled, lower and upper pilot members 55 and 70associated with spring seat members 36 and 59 will coaxially extend intorecesses 75 associated with elastomeric member 74 to keep theinterrelationship of these members aligned. The same is true for each ofthe other elastomeric members 71, 72 and 73 referred to above.

In operation, each of elastomeric members 71, 72, 73 and 74 provides theequivalent of a spring having a progressively increasing spring ratewith progressively increasing loads. What is even more significant aboutthe present invention is the fact that each of these elastomers is ableto dampen and absorb loads in all three and combinations of thevertical, transverse and longitudinal directions. Referring, as anexample, to elastomeric member 74, shown in FIG. 4 as beingrepresentative of each of the elastomeric members described above, it isseen that vertical forces transmitted between upper and lower springseat member 59 and 44 are absorbed by the compression of elastomericmember 74 against the spherical or concave or cup-shaped surfaces 66 and51 of these same seat members. During this compression of elastomericmember 74, the opposing and surrounding wall portions 46, 47, 60 and 61as sociated with the respective upper and lower spring seat membersprevent elastomeric member 74 from deforming in an arbitrary anduncontrolled manner. On the contrary, the presence of these wallportions serves to limit the deformation of elastomeric member 74 and tocontrol the spring rate characteristic exhibited by this sameelastomeric member. During this compression, for example, pilot members'70 and 55 associated with upper and lower spring seat members 59 and44., respectively, maintain alignment between the upper and lower springseat members and the elastomeric member captively held therebetween. Inaddition to defining the extent of deformation of elastomeric member 74,wall portions 46, 47, 6t) and 611 further prevent the undesirable escapeof this elastomeric member during other than vertical compressiveforces.

These same vertically extending wall portions 46, 47, 60 and 61 furtherserve to provide bearing surfaces against which elastomeric member 74may come to bear during times when transverse or longitudinal forces areexerted between upper and lower spring seat members 59 and 44. Morespecifically, transverses forces result in a compression of elastomericmember 74 against wall portions 47 and 61, while longitudinal forcesresult in compression of elastomeric member 74 against wall portions 46and 60. Of course, during operation of a railroad freight car,combinations of vertical, transverse and longitudinal forces occur andelastomeric member 74 is able to accommodate each and all of theseforces separately and simultaneously, while exhibiting a progressivelyincreasing spring rate.

During the exertion of transverse and longitudinal forces uponelastomeric member 74, for example, the presence of pilot members and 55becomes increasingly important in that substantially vertical alignmentbetween upper and lower spring seat members 5 and 44 is maintained. Itshould also be noted that because of the substantially spherical shapeof elastomeric member 74, for example, forces and vibrations exerted indirections which are other than strictly vertical, transverse andlongitudinal are easily accommodated due to the arched upstanding anddepending presence of wall portions 46, 47, 60 and 61 associated withupper and lower spring seat members 59 and 44. What has just beendescribed for elastomeric member 74 and its associated upper and lowerspring seat members is equally true for each of elastomeric members 71,72, 73 and their respective upper and lower spring seats.

The present invention further contemplates the use of elastomericmembers which are of a shape other than spherical and which arecompressively restrained between other than concave or cup-shaped seats.FIGS. 6 and 7 illustrate but two variations of elastomeric memberconfiguration contemplated by the present invention. In FIG. 6, avertically upstanding solid cylindrical elastomeric member 76 isillustrated disposed intermediate and between opposing pairs of convexsurfaces 77 and 78, and 79 and 80, respectively. These convex surfaces'77, 78, 79 and 80 bear against the outer convex cylindrical surfaces ofelastomeric member 76 in a substantially horizontal plane, while upperand lower convex bearing surfaces 81 and 82 (not shown) bear against thesubstantially flat upper and lower surfaces of cylindrical elastomericmember 76. By providing this configuration, it is possible to provide anelastomeric configuration which yields differing and varying spring ratecharacteristics in a horizontal plane than that exhibited in thevertical plane. Thus, different spring rates are achieved with the useof elastomeric member 76 to counteract compressive vertical forces andvibrations than the compressive transverse and longitudinal forcesaccommodated. The abutting convex surfaces of elastomeric member 76 andany one of convex surfaces 77, 78, 79 or 80 will result in a relativelyhigher or greater deformation initially than in cases where the load isless concentrated.

FIG. 7 illustrates an elastomeric member 83 disposed between andintermediate the aforesaid convex surfaces 77, 78, 79, 80, 81 and 82(not shown) described above for elastomeric member 76. Elastomericmember 83 represents an illustration of yet another shape of elastomerwhich may be utilized according to the present invention. In this casefour substantially flat vertically extending sides or faces 84, 85, 86and 87 bear against and are compressively resistant to movement betweenconvex surfaces 77, 78, 79 and 80. Likewise, upper and lowersubstantially flat faces which have not been designated by referencecharacter abut and interact with convex surfaces 81 and 82 (not shown).

Thus, as just described in the present specification, it is seen thatsignificant improvements and novel structure distinguish the presentinvention from that disclosed and described in my previous US. Pat. Nos.

3,572,745 and 3,687,478, wherein the combination of elastomers and seatsare mounted such that axial compression of the elastomer in a singledirection is its sole purpose. In these previous applications andpatents, transverse forces are not resisted by this same elastomericmember but rather by large radial bearings, and at the same timelongitudinal forces are resisted by torque rods of a conventional type.In the present invention, on the other hand, the use of a singleelastomer between cupped seats is expanded to include not only verticalforces but also transverse and longitudinal forces as well. In thepresent invention, the use of pairs of elastomeric members betweencupped seat members is utilized on either side of railroad freight cars,for example.

Vertical loads deform the elastomeric members radially, increasing thediameter of the respective elastomers such that contact is made with theopposing arched walls integral with the upper and lower spring seatmembers. Yet further increases in vertical loads result in furtherflattening of the outer diameter of the elastomer toward a squaredcontour at these retaining walls.

It is important to note here that the suspension according to thepresent invention is applicable to a single axle car truck, as well asthe double axle car truck described in FIGS. l7 above. In the case ofthe use of the present invention with a single axle car truck, the upperspring seat members are fixed to the car body bolster, without kingpins,centerplate or side bearings since there is no oscillation between thecar body and the single axle car truck. It is also important here tonote that where the present invention is applied to a tandem axle cartruck, the upper spring seats are affixed to the side frame member oneither side of the car as described above. In these cases, the load isdirectly over the midlength of the side frame without transfer of weightto the truck bolster and the body centerplate. Thus, the truck bolstermerely serves to tie the opposing side frames together to preservelongitudinal parallelism of the opposing axles and side frames, whilesimultaneously affording a or 6 vertical variation between diagonalwheels. To reduce transverse forces at switch points and curves, thekingpin is offset inboard of the car truck center, as shown in FIG. 3.The truck bolster 18 thus serves to position the car truck in aswivel-type relationship to the car body, and transmits the brake forcestherebetween.

Another point of novelty of the present invention resides in the absenceof lost motion, clearance or transverse backlash between the journal boxassemblies 25 and 26 and the car body itself. The umdamped columnarhelical springs of existing structures results in transverse shimmy oflow frequencies which can be dampened out on a perfectly straight leveltest tract by insertion of steel-faced rubber isolators between thecenterplates and the side bearings of such suspensions. This dampeningcomes into play as the car body rolls transversely on the car truck.

It is significant to note that, of course, all tracks or rails are notstraight or level or smooth, or even of a standard gauge. Thus carhunting is often suspected of causing some derailments of railroadfreight cars. In the present invention, movement in vertical, transverseand longitudinal directions are progressively restrained in relation tothe sprung mass of the car body and its load, with integral dampeningthrough a relatively high hysteresis restrained elastomeric member. Theapplication of an unbonded spherical elastomeric member compressivelyrestrained between cupped seats may also be applied to replacement ofconventional nests of helical undamped springs supported on the side ofcar frames and supporting the free floating truck bolster. Thesuspension system according to the present invention is self-centering,self-damping, and progressively resistant to increased forces invertical, transverse and longitudinal directions. Thus, in addition tothe objects of this invention previously set forth, it is a furtherprincipal object of this invention to provide a positive metallic seatbetween which the elastomer is compressively restrained vertically,transversely and longitudinally with respect to an opposing seat,without dependence upon shear forces in the elastomer to withstandforces of maximum amplitude in each of the vertical, transverse andlongitudinal directions. Another principal object of this invention isto provide a relatively lower spring rate for an empty car structurethan for a loaded car. yet another object of this invention is to avoidinstability of ride which often results from undamped harmonic movementsin what is recognized as being conventional transversely unstable cartrucks. Finally, it is another object of this invention to provide anon-bottoming suspension system with inherent selfdamping in transverse,vertical and longitudinal directions, for a loaded freight car.

The invention described above for FIGS. 1-7 is quite novel in that thestructural design includes truck side bearings or assemblies not shownon which all of the load is carried directly, without the use of acenterplate. The truck side frames 17 are interconnected by a removableflat bolster 18, inboard of which is kingpin trunnion assembly 21 istrunnioned in a shortened wheel base truck to reduce transverse forcesencoun tered at curves and switch points.

The vertical dynamic forces and the transverse-roll static forces areboth absorbed by compression of spherical elastomeric members 71, 72, 73and 74, each of which is restrained between pairs of cupped upper andlower spring seat members, whereby a progressively increasing springrate is operationally achieved in suspensions of an empty car, a loadedcar, and the transverse roll of a loaded car.

The vertically extending flanges or walls associated with the upper andlower spring seat members which captively hold each of the sphericalelastomers are matched by similar flanges disposed 180 degreestransversely of its paired mate, to contact the perimeter of the thenloaded elastomer in resisting the static forces of transverse roll,while at the same time the elastomer is compressed by weight of theloaded car. Otherwise, without the present structure described here, thestaticinduced deflection would result in percent of the deflectioncaused by dynamic forces of the same amplitude. As the ratio of staticto dynamic deflection is 1.5 to 1.0 in an elastomer of such highhysteresis damping quality, the present invention provides a novel andbeneficial result. All four pairs of upper and lower spring seats oneach side of a tandem car truck are disposed or located to resisttransverse forces to the right as well as to the left of the line oftravel of the railroad freight car.

Direct transverse forces, such as those created at switch points andcurves, are likewise resisted by the above-mentioned spring seatvertical walls or flanges,

which augment the shear force resistance of the spherical elastomersdisposed between the vertically spaced spring seats. The longitudinalforces, on the other hand, encountered in braking applications, arelikewise resisted by similar pairs of flanges on all of the same springseats, disposed at 90 from the adjacent flanges which resist transverseforces, and without interference therebetween.

While the range of progressively increasing spring rates obtainable withspherical elastomeric members which are restrained or captively heldwithin and between cupped seats is greater than the ratio of static todynamic deflections of this elastomer, it is to be noted that thelocation of the kingpin assembly has been established inboard to reducethe angle of approach to switch points and curves, thereby lessening thetransverse forces encountered at these points.

The present vehicle suspension system will not provide a constant floorheight with any load, as is presently available with air springsuspension systems. Thus, for a 7.5 inch free diameter elastomerutilized with a 70 ton railroad car, the empty car height will be 1.5inches higher than the loaded car height, while the springs will reflect0.75 inches to the free height of the elastomers. Thus, total workingdeflection of the elastomers is but 30 percent of their free diameter toprovide long life thereof.

The embodiments of the invention particularly disclosed and describedhereinabove are presented merely as examples of the invention. Otherembodiments, forms and modifications of the invention coming within theproper scope and spirit of the appended claims will, of course, readilysuggest themselves to those skilled in the art.

What is claimed is:

1. A railraod vehicle truck suspension structure for use with railroadfreight cars having at least one axle, or the like, comprising, incombination: a journal box disposed at each transverse end of said axle;left and right longitudinally extending vehicle side frame membersdisposed at each transverse side of said freight car; first and secondlower seat members disposed, respectively, fore and aft of the axis ofsaid axle and each supported by a journal box; first and second spacedupper seat members, respectively, said upper seat members being integralwith said left frame member during use; first and second elastomericmember disposed intermediate and captively held between each of saidfirst upper and lower and said second upper and lower seat members,respectively, said elastomeric member providing progressively increasingresistance to vertical, transverse and longitudinal operating forcestransmitted between the sprung mass and said axle; each of said lowerseat members comprising a cup-shaped lower base portion thereof integralwith upstanding, arcuately extending lower wall portions whichcollectively extend substantially half-way about said lower baseportion, said lower base portion having bearing surfaces which engageone of said elastomers, said lower upstanding wall portions havingcurved surfaces which engage one of said elastomers; each of said upperseat members comprising a cup-shaped upper base portion thereof integralwith depending, arcuately extending upper wall portions whichcollectively extend substantially half-way about said upper baseportion, pairs of said upper and lower seat members being operatively located such that said upper and lower wall portions are disposed inopposite relationship with respect to each other about one of saidelastomers, thereby captively limiting movement of the elastomer, saidcaptive elastomer resisting horizontal movement of said upstanding anddepending wall portions towards each other and further resistingvertical movement of said upper and lower base portions towards oneanother, thereby isolating rail-induced forces in each axle from thevehicle sprung mass.

1. A railraod vehicle truck suspension structure for use with railroad freight cars having at least one axle, or the like, comprising, in combination: a journal box disposed at each transverse end of said axle; left and right longitudinally extending vehicle side frame members disposed at each transverse side of said freight car; first and second lower seat members disposed, respectively, fore and aft of the axis of said axle and each supported by a journal box; first and second spaced upper seat members, respectively, said upper seat members being integral with said left frame member during use; first and second elastomeric member disposed intermediate and captively held between each of said first upper and lower and said second upper and lower seat members, respectively, said elastomeric member providing progressively increasing resistance to vertical, transverse and longitudinal operating forces transmitted between the sprung mass and said axle; each of said lower seat members comprising a cup-shaped lower base portion thereof integral with upstanding, arcuately extending lower wall portions which collectively extend substantially half-way about said lower base portion, said lower base portion having bearing surfaces which engage one of said elastomers, said lower upstanding wall portions having curved surfaces which engage one of said elastomers; each of said upper seat members comprising a cupshaped upper base portion thereof integral with depending, arcuately extending upper wall portions which collectively extend substantially half-way about said upper base portion, pairs of said upper and lower seat members being operatively located such that said upper and lower wall portions aRe disposed in opposite relationship with respect to each other about one of said elastomers, thereby captively limiting movement of the elastomer, said captive elastomer resisting horizontal movement of said upstanding and depending wall portions towards each other and further resisting vertical movement of said upper and lower base portions towards one another, thereby isolating rail-induced forces in each axle from the vehicle sprung mass. 